It is known that the hypoxic response in microenvironment in a body affects organ formation during development, proliferation of stem cell, and the like. Also, it is known that the effect of the hypoxic response relates to disease such as cancer and ischemic disorder.
Also, the hypoxic environment regulates expression of a variety of genes and controls cell response such as cell growth, differentiation, apoptosis and the like.
On the other hand, a variety of anticancer agents has been developed for cancer therapy. For example, there are mentioned as anticancer agent: cytarabine, fluorouracil, mercaptopurine and thioguanine as DNA synthesis inhibitors; vinblastine, vincristine and procarbazine as vinca alkaloids; mustine, cyclophosphamide and cisplatin of alkylating agent; actinomycin D, doxorubicin, mitomycin, mitramycin and bleomycin as antibiotics; and glucocorticoid, estrogen, anti-estrogen and androgen as steroid hormones and the like.
Cytarabine inhibits DNA polymerase, and fluorouracil inhibits thymidylate synthase to suppress pyrimidine synthesis. Mercaptopurine or thioguanine inhibits purine synthesis. Vinblastine or vincristine acts specifically to DNA in M phase, and destroy the spindle by binding to tubulin to stop mitosis of a cell. Procarbazine causes depolymerization of double strand DNA to inhibit DNA synthesis, and mustine, cyclophosphamide, cisplatin and the like cause covalent cross-link to inhibit DNA synthesis. Actinomycin D, doxorubicin, mitomycin, mitramycin and the like are intercalator, which are intercalating between a space formed by base pairs in double strand DNA, and block RNA synthesis. Also, bleomycin causes the breakage of the double strand DNA. Glucocorticoid, estrogen, anti-estrogen, androgen and the like inhibit the protein synthesis after RNA synthesis.
Other than that, a lot of anticancer drugs have been developed and used for treatment to exert a certain effect of treatment.